Unitary bathrooms have been used in the marketplace for many years. A unitary bathroom is generally constructed of a base, a plurality of sidewalls and a ceiling. Prior art unitary bathroom utilizes light and thin sheet material with insufficient strength and hardness. In addition, coating material is tedious, decoration style is limited, and there is poor texture. Moreover, it will be easily deformed and its color will come out after long time use. Additionally, the unitary bathroom suffers from unsafe assembly and is susceptible to peeling off caused by aging and accordingly, the lifespan of the unitary bathroom is also shortened.